Patching leather



Dec. 14, 1926. 1,610,519

K. L. HERRMANN PATCHING LEATHER Filed July 28. 192;

INVENTOR ATTORNEY Patented Dec. 14, 1926.

warren stares rarest orrics.

KARL L. I-IERRMANN, OF DETROIT, MICHIGAN, ASSIGITOR TO THE STUDEBAKER COB- IPORATIO'N, OF SOUTH BEND, I1 TDIAI TA, A CORPORATION OI NEW JERSEY.

PATCHING LEATHER.

Application filed July 28,

This invention relates to the patching of leather and has for its objects the providing of a particular form of patch that when finished will not be detectable, which will provide a means whereby patched leather will be as strong as unpatched leather as far as practical uses are concerned, which for practical results may be used for any purpose that unpatched may be used for, and which will be economical and practical touse.

4 Up to the present time, as far as I have been able to determine, there has been no practical method of patching leather so that it may be used in any place that unpatched leather may be used. The method that has been followed heretofore has been to trim the edge of the hole to the desired shape, which is with substantially perpendicular sides in relation to the surface of the leather, cut out a patch to approximately fit the hole, and glue the same in place, sometimes with another piece of leather at the back overlaying the patch. This method seldom furnishes an accurate patch and the surface being held by the glue is so small in comparison to the size of the patch, particularly with larger patches, that there is not suiiicient strength in the anchoring of the patch to withstand the use that unpatched leather may be put to, and also is such that the patched portion is readily detectable. When a piece overlaying the patch is glued to the back the result is that the patched portion is not as pliable as the unpatched portion and it also makes the leather at the patched point thicker than the rest of the leather which prevents its use in many places.

As is known to those familiar with the art, it is common for hides to have several grub or other holes therein, most of which vary from perhaps a quarter inch or so in diameter down to a pin or nail hole. In event. for instance, a piece of leather is needed for an automobile seat cushion, which piece of leather is preferably of onepiece and of such a size that it will take approximately one half of an ordinary hide, and which must not show a patch, it is necessary to have a hide with no holes therein, or if there are one or two holes, it isnecessary to cut out a strip across the piece "corresponding 1923. Serial No. 654,480.

with the width of one of the panels of the cushion and sew the piece together so that the sewed portion will fall in one of the depressions of the panel. Inasmuch as it is a frequent occurrence to have such grub or other holes in hides, and because of the rea sons before stated it is undesirable and relaively expensive to cut out the portion with the holes in and to sew the pieces of leather together, it is a natural result that hides without holes cost considerably more than hides having such holes therein and these latter hides are somewhat of a loss to the owners of the same.

The principal object of my invention is to provide a patch for such holes that will allow patched leather to be used in any place that unpatched leather may be used, thereby materially reducing the cost of leather employed where unpatched leather or its equivalent is necessary and at the same time prevent the loss now due to leathor with holes therein.

My invention consists in providing the hole to be patched with very flat or divergent sides. that is, the diameter of the hole on one side is as near the same size as the original hole as is practical and the diameter of the same hole on the other side of the leather is of a very much larger diameter, making the angle of the sides of the hole very small in relation to the surface of the leather and providing a large surface for the sides of the hole. A patch, previously formed to correspond to the size and general dimensions of the hole is then glued in place and because of the very large area in contact between the patch and sides of the hole a very strong patch results. The leather may then be worked down to any desired thickness if necessary and finished in the usual way. When leather so patched. and worked down is pressed to show grains and is finishedby applying a coating of pyroXylin, it is impossible to detect the patch. Such a piece of'leather may be put to any practical use that an unpatched piecemay be put to. I

In order to more. fully describe my invention I will now refer to the accompanying drawings which illustrate an embodiment thereof. In the drawings- Fig. 1 is a plan view of a piece of leather With a grub or other hole therein such as I have described.

Fig. 2 is a plan view of the piece of leather Of Fig. 1 with the hole prepared for a patch as I have explained.

Fig. 3 is a section of the leather of Fig. 2 taken on a line passing thru the center of the hole.

Fig. 4 is a plan view of the patch.

Fig. 5 is a section of the patch taken thru the center of the same.

Fig. 6 is a section taken thru the leather and patch showing the same in final or finished position.

Fig. 7 is a side elevation of a machine suitable for preparing the hole to be patched or for preparing patches for such holes.

Fig. 8 is a plan view from below, of the cutting head of the machine of F ig. 7, and

Fig. 9 is a sectional side elevation of the cutting head of the machine of Fig. 7 taken on the line AA of Fig. 8.

Altho the hole and patch I have shown in the drawings are round, a hole of almost any shape and a patch therefor may be made with as much ease as a round hole and I do not restrict myself in this respect to any stated contour or size of hole. 1 is a piece of leather originally having a grub or other hole 2 as shown in F 1. The hole 2 is prepared for patching by forming it, as shown at 3, Figs. 2 and 3, with very divergent side walls, the angle of the walls with the surface of the leather being indicated as a in Fig. 3. The bottom diameter of the prepared hole 3 is preferably not very much larger than the size of the original hole 2, and the top of the hole 3 is of substantially greater diameter to provide a large area to the side walls thereof. t is a patch for the hole 3 and is formed to substantially the same dimensions as the hole 3, the angle 5 (Fig. between the sides and the surface being the same as angle a of Fig. 3. The side walls of the opening 8 and the sides of the patch t are covered with glue or other suitable material and he patch a is then placed in the opening 3 in a position corresponding thereto and the glue is allowed to set or dry. The piece of leather 1 is then preferably worked down to the proper thickness which to all practical purposes obliterates any sign of the patch. If. as is commonly the practice. the leather is pressed to show grains and is covered with a coating of pyroxylin it is impossible to detect such a patch. Inasmuch as there is such a relatively large area of the leather and patch glued together a very strong patch results, which far practical results are concerned, has been found to be strong as an unpatched piece of leather.

In order to facilitate such patching and to make the same practical, economical. and to place it on a socalled production basis it is desirable to form such holes as are originally in the leather to one of a number of standard sizes and contours and to provide standard patches to fit such standard prepared holes. In such an event the patches and holes may be prepared separately and at ditferent times and boints if so desired, and in the operation of patching the leather the patch may be applied to any corresponding hole in the leather with an assurance that itwill fit perfectly.

In order to realize such a condition it is necessary to provide means for forming uniform patches and uniformly preparing the holes in the leather, to correspond therewith. Altho there are several desirable means that may be adapted for this purpose I have itlustrated in Figures 7. 8 and 9 one particular machine with which the holes in leather may be prepared and with which patch-cs may be formed. It is such that any number of patches may be made or holes prepared to duplicate a standard sized hole or patch.

This machine is composed of a base memher 5 having an upright post 6 which supports and upon which is swiveled an arm 7 which journals and supports the cutting apparatus. A nut 8 threaded on the post 6 be low the arm 7 provides veri cal adjustment for the arm 7.

The removal of the leather about the hole 2 to prepare it as shown at 3 may be done by several different means inciuding grinding or sanding, or cutting with a knife or other edge. In the machine I have illus trated in the drawings I use a knife et and the method I use to remove the leather about the hole 1 by the knife cde'e is to support a button member 9 0n the base under the knife. The button member 9 is; so shaped on its upper surface, over which the piece leather containing the hole 2 to he prepared as at 3 is placed, as to correspond to the shape of the hole to be cut out when the knife is passed horizontally thereover and in close proximity thereto. The bu on 9 is removable so that if the hole is to be round a button whose surface is formed in a corresponding manner is used and if the hole is to be elongated a button whose surface is formed to correspond thereto is used. The leather 1 is placed over the button 9 with the hole 2 on the top, the knife is passed horizontally over the button I) and the leather about the hole 2 is ren'ioved which causes the hole 2 to conform to the de ired shape 3. In the same manner :1 piece of leather without hole therein may be p over the button 9, the knife passed thereover and a patch a results which will tit the liol 3 exactly.

I have found that if a knife is over the button directly from one side other the knife has a tendency to lift the leather after has passed over the center of the button 9, thereby causing the hole' 3 or patch 1 which is being preparedto not match ,the button 9 as desired, but has the effects of digging into the leather 1 on the last part reached which results in a sharper angle to the sides of the hole 3 or patch a: as the case may be. I have found that by revolving the knife so as to begin cutting at the outside edge of the hole 3 or patch l all the way around and gradually bringing it in to the center of the button 9, a hole 3 or patch 4 may be prepared which exactly coincides with the shape of the button 9.

In the machine I have shown in the drawings I provide a cuttin head with mech anism to revolve the knire and to draw it to the center as above described. This cutting head is supported on the arm 7 and has a vertical shaft 10 journaled in and supported by the arm 7, a crank or handle 11 being secured to its upper end and an arm 12 being secured to its lower end. Aknife supporting member 13 is pivoted at 1 1 to the arm 12 on the lower end of the shaft 10 and is provided with a detachable knife blade 15, the center of which is preferably on an arc of a circle whose center is at 1 tand which also passes thru the axial line of the shaft 10. A track member 16 whose face is in a horizontal plane is non-rotatably secured to the lower face of the end of the arm 7 about the shaft 10 and above the arm 12 and knife supporting member 18. A spiral groove or track 17 is cut in its lower face as shown in Fig. 8 and Fig. 9. An upwardly projecting pin or finger 18 is pro vided on the knife supporting member 13 preferably in the same are of a circle as the center of the knife blade 15 as above described. The pin or finger 18 may either be guided only in the track 17 or it may also serve to help support the knife supporting member 13. It is evident that the pin or finger 18 in the track 17 controls the position of the knife blade 15 from the center of the button 9 which in operative position is in line with the axis of the shaft 10. It is also apparent that when the handle 11 is turned, causing the arm 12, knife supporting member 18, and knife blade 15 to turn therewith, the knife blade 15 is caused to move outwardly or inwardly from or to the center of the button 9 in a manner corresponding to the direction in which the handle 11 is turned. thus causing the knife blade 15 to have a rotary motion about as well as a transverse movement to or from the center of the button 9. This movement I have found results in a hole 3 or patch 4 that perfectly matches the button 9 and is there fore a desirable machine for use in so patching leather as I have described.

In the operation of preparing a hole 2 to be formed as at 3, the handle 11 is revolved to cause the knife blade 15 to move to its extreme outward position, the arm 7 is swung back so that the axis of the shaft 10 is in line with the center 6f the button Sand the handle 11 is revolved to cause the knife blade 15 to rotate around and to approach the center of the button 9, thereby removing the leather about the hole 2, forming it as at- 3. It is preferable that some means be provided to hold the leather 1 securely down on the button 9 while the cutting is being done and any suitable means may be em ployed for accomplishing this purpose. I have found that a metal ring (not shown) placed over the leather about the button 9 answers this purpose very satisfactorily.

IVhile in my description I have referred to the patching of leather, I wish it to be understood the term leathefiin both the specification and claims is meant to include all fibrous, homogeneous, or woven material of a pliable nature.

Formal changes may be made in the specific embodiment of the invertion described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. The process of patching leather and like material which consists in mechanically forming holes of a predetermined area and contour to form a tapered seat in a body of leather and like material, in mechanically forming patches from a body of similar material and of substantially the same area, contour and tapered formation as the me chanically-formed hole, and in finally applying the said mechanically formed tapered patch to the said mechanically formed hole and seat of the leather body.

2. The process of filling in holes in a sheet of leather, consisting in removing a portion of the leather surrounding the hole in such a manner as to form a seat tapering outwardly from the outline of the hole on one side of the sheet and of large area as compared with the area of the hole, preparing from similar leather a patch of the same area and contour as the seat formed in the leather and having its under surface complemental thereto and cementing the patch to the seat, whereby the outer surface of the patch is flush with the surface of the surrounding portion of the sheet of leather, and the patched portion is of the same thickness as the surrounding unpatched portion.

3. The process of filling in holes in a sheet of leather, consisting in removing a portion of the leather around the hole in such a manner as to form a seat of an extensive area surrounding the hole and very gradually tapering outwardly from the outline of the hole 011 one side of the sheet, preparing from similar leather a patch of the same area and contour as the seat formed in the leather and having its under-surface coinplemental thereto, and cementing the patch to the seat, whereby the outer surface of the patch is flush with the surface of the surrounding portion of the sheet of leather, and the patched portion is of the Same thickness as the surrounding unpat-ched portion.

Signed by me at Detroit, Michigan, U. S. A, this 10th day of July, 1923. 

